1. Field of the Invention
This invention relates to haloaryl halobenzene sulfonates and to flame retardant polymeric compositions containing said sulfonates as flame retardants.
2. Description of the Prior Art
During the past several years, a large number of flame retardants have been developed for use with an almost equally large number of flammable materials. Cellulosic materials such as paper and wood and polymeric materials such as polyolefins, polyesters, polyurethane and polystyrene are just two examples of materials for which flame retardants have been developed. For any class of flammable materials, such as synthetic type polymers, those skilled in the art have long been aware that some flame retardant additives are more effective in polymers and polymeric compositions than other flame retardant additives. This is because the efficacy of any flame retardant in polymers or polymeric compositions is measured not only by the flame retardant capability of the additive but also by the ability of the additive to improve or modify, or at least not to detract from, other physical or mechanical properties of the polymer or polymeric compositions. The mere fact, therefore, that some flame retardants contain halogen and sulfur atoms does not assure that any given halogenated or sulfur containing compound will impart usable flame retarding characteristics to all or even to any polymeric system. Furthermore, as those skilled in the art have improved the flame retardancy of many polymeric materials, they have been simultanously required to provide the necessary flame retardancy with a minimal effect upon other properties of the polymer such as the light stability, processability, and flexural, tensile and impact strengths. Also, it has been the desire of those involved in the art of flame retardants to provide flame retardants having a durable lasting effect. Balancing all of the foregoing considerations and thereby developing polymeric compositions with good flame retardant characteristics as well as a satisfactory balance of other properties is, consequently, a task which has in the past and presently continues to require the exercise of a high degree of inventive skill.
The prior art considered in the preparation of the instant application in U.S. Pat. Nos. 2,148,928 to Meuron, 2,486,417 to Jackson et al, 2,567,008 to Britton et al., 2,860,168 to Erickson, 3,125,604 to Robbins, 3,228,876 to Larson et al, 3,395,232 to White, 3,818,102 to Partos, 3,850,972 to Garalski, and German patent application No. 2,508,993.
In particular, U.S. Pat. No. 2,148,928 to Meuron discloses mothproofing compositions containing as active ingredients thereof, inter alia, p-chlorobenzene sulphonic acid ester of p-chlorophenol, p-chlorobenzene sulphonic acid ester of phenol, o- m- and p-cresol and their mixture; p-chlorobenzene sulphonic acid ester of o-chlorophenol; p-chlorobenzene sulphonic acid ester of dichlorophenol; p-chlorobenzene sulphoic acid ester of p-amylphenol; di-(p-chlorobenzene sulphonic acid ester) of dihydroxy-diphenyl, di-(p-chlorobenzene sulphonic acid ester) of dihydroxy-diphenyl sulphone; di-(p-chlorobenzene sulphonic acid ester) of di-phenolisatin; 3,4-dichlorobenzene sulphonic acid ester of o- or p-chlorophenol; and 2,5-dichlorobenzene sulphonic acid ester of o- or p-chlorophenol. This patent fails to disclose the instant compounds of formula I wherein m+n=4 to 10, and their use as flame retardants in polymeric compositions.
U.S. Pat. No. 2,567,008 to Britton et al discloses aryl esters of 4-chlorobenzene sulfonic acid of the formula ##STR3## wherein one X represents a phenyl radical and the other X represents hydrogen. These compounds are disclosed as being of value as toxic constituents of parasiticidel compositions. This patent fails to teach the instant compounds or their efficacy as flame retardants for polymeric compositions.
U.S. Pat. No. 3,850,972 to Goralski discloses phenyl esters of bromo-methanesulfonic acid corresponding to the formula ##STR4## wherein X represents halo, halo lower alkoxy, nitro, trifluoromethyl, or phenoxy and n represents an integer from 1 to 5 for halo groups and from 0 to 1 for groups other than halo; Y represents halo, nitro, or lower alkyl; m represents an integer from 0 to 2; and m+n does not exceed 5. These compounds are disclosed as having antimicrobal and fire retardant activity.
German Pat. No. 2,508,993 discloses flame retardant aryl mono- or di-sulphonic acid esters of polybromo phenols of the formula ##STR5## where R.sup.1 is H, 1-8 carbon alkyl, Br or Cl; R.sup.2 is the same as R.sup.1 or is ##STR6## Hal is Br or Cl; x is 2-4, n is 3-5; y is 4-x, m=5-n, R.sup.3 is Br, cl or ##STR7## where Z is --O--, --S--, --s(O).sub.2 --, 1-4 carbon alkylene or alkylide.
These compounds are disclosed as being flame-retardants in polyolefins, especially polyethylene and polypropylene.